Air compressor



Nov. 8, 1932.

F. ACKERMAN v AIR COMPRESSOR 3 SheetsA-Sheet 1 Filed May 11. 1931 Z m 5 W N w .m T WWW 4 m ML Q. r; 5

Nov. 8, 1932. F. ACKERMAN 1,886,359

AIR COMPRESSOR Filed May 11, 1 931 3 She ets-Sheet 2 Nov. 8, 1932. F. ACKERMAN 1,886,359

I AIR COMPRESSOR Filed May 11. 1931 s Sheets-Sheet 3 FITT PMEK;

Patented Nov. 8, 1932 UNITED STATES FRANK ACKERMAN,

COMPANY, OF WELLSTON, MISSOURI, A CORPORATION OF MISSQURI AIR corms-Essen Application filed May 11, 1931. Serial No. 536,416.

This invention relates to air compressors.

One object of my invention is to provide an air compressor which is of such design and construction that there is little tendency for carbon to be formed and deposited on the valves, valve seats and other internal surfaces of the'head of the compressor.

Another object is to provide a valve structure for compressors, which, in addition to being capable of being. installed and removed as a unit, has the following desirable characteristics: non-warping valves of rugged design that have seat-engaging portions of minimum circumference as compared to the area of the ports controlled by said valves; a valve seat member that can be easily maintained in gas-tight relationship with the head of the compressor; and air ports or passageways of suflicient size or area to eliminate clogging and also to reduce to a minimum the heating of the inflowing air.

And still another object is to provide an air compressor, which is of such design and construction that deposits of dirt, carbon or other foreign matter on the internal surfaces of the head or on the valve structure in the head, will not interfere with the removal of the valve structure, or make it dificult to withdraw the valve structure as a unit from the head. Other objects and desirable features of my invention will be hereinafter pointed out.

Figure l of the drawings is a vertical, transverse sectional view of an air compressor constructed in accordance with my invention.

Figure 1 is a detail sectional'view, illustrating the cushioning device that is interposed between the bottom abutment member and the portion of the head that supports said member.

Figure 2 is a top plan view of the valve seat member.

Figure 3 is a fragmentary view of the cushioning device above referred to.

Figure 4 is a top plan view of the bottom abutment member, showing two of the inlet valves.

Figure 5 is a bottom abutment member; and

plan view of a top tom to provide the head of Figure 6 is a bottom plan view of the valve seat member. i

It has heretofore been the, universal cusan aircompressor with cooling fins or with a water jacket, for the purpose of abstracting or absorbing heat from the valves and other parts of the head. One serious objection to air compressors of conventional design is that carbon 'accumulates rapidly on the valves, valve seats and other internal surfaces of the head, thus making it necessary to clean the internal parts of the head at frequent intervals, I have discovered that the formation and deposition of carbon on the internal parts or surfaces of the head of an air compressor is caused by the highly heated compressed air escaping from the cylinder, coming in contact with surfaces or parts on, the head that are at a lower temperature than the temperature of said air and which cause the oil vapors in the air to condense, withthe result that carbon will be formed and deposited onv the cooler surfaces or parts in the head over which the. compressed air fiows inescaping from the cylinder of the compressor;

In order to overcome or remedy the above described inherent defect of air compressors of conventional design, I depart radically from standard air compressor practice by omitting or dispensing with heat radiating fins or a water jacketv or equivalent means, for abstractingor absorbing heat from the head of a compressor and the valves and other parts carriedby the head. In my improved compressorI provide an adequate cooling system or means for the side wall of the cylinder, for the piston andpreferably for the portion of the head immediately adjacent the upper end of the cylinder, with a view to keeping the internal temperature of the cylinder-down as low as possible, so that there will be a minimum vaporization of the lubricating oil used in the compressor, but I design and construct the head so that theportions of same through which the escaping air flows, will be maintained at a sufficiently high temperature to eliminate or-substantially eliminate the con densation of the oil vapors in said escaping side wall of the 0]? ST. LOUIS, MISSOURI, ASSIGNOR TO CURTIS MANUFACTURING oil vapors in said air to condense and form carbon deposits.

So far as the above described broad idea is concerned, i. e., providing an air compressor with a hot head, it is immaterial what type or kind of valve structure the head is equipped with. However, I prefer to equip the compressor with a valve structure of the kind herein illustrated, as such a valve structure is of rugged design; it is capable of being easily installed and removed, even though long and continuous usage has caused dirt, carbon or other foreign matter to become deposited inside of the head, and it is of such design that it reduces to a minimum the heating of the inflowing air. Briefly, described, said valve structure comprises diskshaped inlet valves and discharge valves, a removable valve seat member that has a gastight joint with the head, abutment members for the valves combined withsaid valve seat member in such a way as can be easily installed-and removed, and a removable portion on the head that carries said valve structure and which normally closes an opening in the head'through which said valve structure can be withdrawn. In order that dirt, carbon or other foreign matter which may become deposited in the head,

will not interfere with the removal of the valve structure, the head and valve structure are so designed that there are no surfaces on the head that have a close lit with the valve structure, and through which or over which the valve structure must be moved during the operation of withdrawing the valve structure from the head.

. In the accompanying drawings which rep.- resent the preferred form of'my invention, A designates the cylinder of an aircompressor, B designates the piston in said cylinder, and C designates as an entirety the head of the compressor, which may either be integrally connected or detachably connected to the cylinder A. The head C is provided with a valve structure that comprises a valve seat member D,- a plurality of disk-shaped inlet valves 1 that act on flat seats formed on the underside of the valve seat member D, and a plurality of disk-shaped discharge valves 2 that act on valve seats formed on the top side or upper side of the valve seat member D. A top valve abutment member E is combined with the valve seat member D, so as to limit the upward movement of the discharge valves 2 relatively to their seats, and a bottom to form a unit that valve abutment member F isarranged on the underside of the valve seat member D, so as to limit the downward movement of the illlet valves 1 relatively to their seats. The top valve abutment member may either be integrally connected with the valve seat member, or formed as a separate part that is attached to and clamped to the valve seat member. The valve seat member D is provided with air inlet ports or passageways 1 which communicate at their upper ends with an air intake passageway 3 in the top valve abutment member E, and the bottom valve abutment member F is provided with numerous air ports or passageways 1 disposed so as to permit air to enter the cylinder A when the inlet valves 1 unseat during the suction stroke of the piston B. The valve seat mem ber D is also provided with air dischargeports or passageways 2* whose lower ends communicate with some of the air ports or passageways 4 in the bottom valve abutment member F and whose upper ends communicate with discharge passageways formed by spaces between guides, hereinafter described, that surround the discharge valves 2.

As shown in Figure l, the valve structure is installed in the head C of the compressor in such a manner that the compressed air which escapes from the cylinder past the discharge valves2 during the compression stroke of the piston, will enter a discharge chamber and eduction passageway 6 formed in the head. Said discharge chamber or eduction passageway 6 is proportioned and designed so that the highly heated air, in escaping from "the cylinder, will not impinge directly upon the walls of said chamber,

andthereafter said highly heated air will travel: through said chamber 6 to the outlet of same without remaining in constant engagement with said walls or exerting a scrubbing action on said walls. The inlet valves 1 are pressed upwardly against their co-actin g seats on the underside of the valve seatmember D, bymeans of springs 1 that are seated in pockets formed in the top face of the bottom valve abutment member F, and the discharge valves 2 are forced downwardly into engagement with their co-a'ctin seats on the top side of the member D, by means of springs 2 that are seated in pockets 5 in the top valve abutment member E. The inlet valves 1 are maintained in concentric relationship with the air ports or passageways which they control by means of vertically-(1isposed guides 1 on the bottom abutment member F, and the discharge valves 2 are guided and maintained in concentric relation with the ports or passageways which they control, preferably by means of substantially tubular guides 2- formed preferably from sheet metal stainpings and mounted on tubular portions 2 on the top abutment member E that are located directly over the discharge valves 2.

Each of such tubular guides 2 is provided with a concentric row of'spaced fingers 2 as shown in Figure 5, that surrounds one of the discharge valves, and thus accurately holds said valve in alignment with its seat,

the spaces between said fingers 2 serving as passageways for the escaping air, as previously described. The valves 1 and 2 con sist of flat metal disks that are rugged enough to prevent the valves from warping, and as shown in Figures 2, 4: and 6, the air ports or passageways in the members D, E and F are made relatively large for the two-fold purpose of eliminating clogging and also to reduce to a minimum heating of the inflowing air, as would be liable to occur if the inflowing air were drawn through numerous ports or passageways of relatively small cross-sectional area.

As shown in Figure 1, the bottom valve abutment member F fits in a bore in the bottom face of the cylinder head, and is supported in the head by a laterally-projecting flange 7 at the upper end of said abutment member, which laps over a shoulder on the head. The valve seat member D is of greater diameter than the bottom abutment member F, andis arranged so that the peripheral portion of the bottom face of saidmember D bears upon a machined surface or seat 8 on the head. It is absolutely essential that a gas-tight joint be maintained between the valveseat member D and the seat 8 on the head on which said member bears, and accordinglyfl proportion the valve seat member D and the top abutment member E in such a way that when they'are combined and installed in the head, the abutment member E will exert a downward force or thrust on the valve seat member D at a point close enough to the center of said member D to cause the peripheral portion of the valve seat member to be held tightly against the seat 8 on the head. In other words, when the top abutment member is formed by a part that is separate and distinct from the valve seat member, said top abutment member E is provided at its center with a clamping portion 10 that is adapted to act upon a portion 11 at the center of the valve seat member D and exert downward pressure on said member'near' enough to the center of same to insure the peripheral portion of the member D contacting throughout its entire area with its seat 8 on the head- Due to the fact that the peripheral portion of the valve seat member D must be maintained in gas tight relationship with the head, a considerable problem is involved in supporting the bottom abutment member F, because said bottom abutment member must be securely supported, but it must not interfere with the proper seating of thevalve seat member D on the head. I have solved the problem by interposing a cushioning device G between the bottom abutment member F and the portion of the head which supports said member, as shown in Figure 1*, said cushioning device causing the bottom abutment member to be held securely, but at the same time permitting said bottom abutment member to yield sufliciently to insure the valve seat member bearing tightly upon its seat. The cushioning device G may be formed easily from a brass ring provided with portions G, as shown in Figure 5, that are adapted to deform or mash down more or less during the operation of clamping the valve seat member on its seat 8, thereby causing the bottom abutment member to be clamped securely between the head and the valve seat member D without interfering with the proper seating of said member D. A gasket 12 is interposed between the co-acting portions 10 and 11 of the top abutment member and the valve seat member "D, so as to insure a gas-tight joint between said parts.

As previously stated, my improved valve structure is of such design that it can be easilywithdrawn from the head, even though the compressor has been in long and continuous use and considerable quantities of dirt, carbon or other foreign matter have accumulated on the internal surface or parts of the head. I attain this highly desirable result by designing the head of the valve structure in such a way that there are no parts on the head that have a close fit with the valve structure and through which or over which the valve structure must be moved during the operation of withdrawing same from the head. Thus, as shown in Figure 1, the periph eral edge of the valve seat member Dis sepa rated by a space of considerable size from the portion of the head that surrounds said valve seat member. As shown in Figure 1, the valve structure, as an entirety, is arranged inside of the chamber 6 in the head and is carried by a plate or other suitable member 13 that normally closes an opening 1a in the top wall of the chamber 6 in the head, a gasket 13 being interposed between the plate 13 and the part of the head over which said plate laps. The plate or closure 13 can be detachably connected to the head in any suitable way, as, for example, by means of nuts 15 screwed onto stationary stubs on the head that project upwardly through the plate 13. Said plate. 13 is provided with a portion 17 of considerably smaller diameter than the diameter of the hole 14:,inwhich is positioned a device 18 that is used to exert pressure on the top abutment member E in a direction to force said member downwardly so as to pro duce a gas-tight joint between the valve seat member D and the seat 8 for said member. In the form of my'invention herein illustrated the device 18 consists of a nut that is portion 17 of the closure plate 13, and a pack-.

ing 19 is arranged between the lower end of said nut and an inclined surface 20 on .the top abutment member E, so that when the nut 18 is screwed downwardly, the packing 19 willbe compressed and a tight joint will be produced between the closure plate 13 and the top abutment member E. As previously stated, the act of tightening the nut 18 also causes the valve seat member to be forced tightly onto the seat provided for same on the head. a

When it becomes necessary or desirable to inspect or replace the valves, this can be accomplished quickly and easily simply by removing the closure plate 13 and then withdrawing the valve structure upwardly through the hole 14 in the head. As there are no closely fitting surfaces on the head through which or over which the valve structure must be moved in the operation of withdrawing it, there is no liability of the valve structure sticking in the head, due tothe accumulation of di t, carbon or the like on surfaces on the head or on the valve structure which are of substantially the same size and which slide one upon the other in the operation of withdrawing the valve structure.

In order that the valve structure may be installed and removed as a unit, means is provided for clamping the bottom abutment member to the valve seat member, or for clamping the three parts D, E and F together, if the top abutment member is not joined integral with the valve seat member. In the form of my invention herein illustrated the said means consists of a bolt 21 arranged with its lower end portion projecting through a center hole in the valve seat member D and screwed into an internally threaded hole 22 in the bottom abutment member F, and having its upper end portion projecting upwardly through a cross web 23 in the air intake )assageway 3 of the top abutment member J, said bolt being threaded to receivea nut or the like 24:, which, upon being ti htened, forces the top abutment member towards the valve seat member. The bolt 21 is provided intermediate its end with a non-circular-shaped portion 25 that is adapted to be engaged by a wrench or other suitable tool in the operation of screwing the threaded portion at the lower end of the bolt into the hole 22 provided for same in the bottom abutment member, so as to clamp the valve seat member to thebottoln abutment member. In order to maintain the valve seat member D in such a position with relation to the bottom abutment member F that the ports or air passages in the valve seat member will register with the air ports or passageways in the bottom abutment member, one of said members is provided with a pin 26, as shown in Figure 1, that is adapted to enter a hole 27 in the other member, whereby relative rotative movement of said members is prevented.

As previously stated, means isprovided for cooling the side wall of the cylinder of the compressor, with a view to keeping the internal temperature of the cylinder down as low as possible, so as to tend to prevent the lubricating oil from becoming vaporized. The means that is used for this purpose will generally consist of a water jacket 28 for the side wall of the cylinder, and if desired, the piston B of the compressor may be provided with radiating fins 29 or any other suitable means that will tend to carry off heat that is developed in the cylinder and piston during the operation of compressing the air. The water jacket 28, instead of being extended over the major portion of the head, as has heretofore been the universal practice, terminates adjacent the point where the head joins the side wall of the cylinder, thereby producing a compressor whose head will remain in a highly heated condition when the compressor is in operation, due to the absence of any means in or on the head which will absorb or conduct away heat that the head takes up from the compressed air escaping from the cylinder. If desired, the water jacket may be extended into the head sufficiently to cool the part of the head that is immediately adjacent the upper end of the side wall of the cylinder, but to all practical intents and purposes, the head and the parts or elements carried by the head are uncooled, and hence, will remain at a sufficiently high temperature when the compressor is in operation, to prevent the entrained oil vapors in the air that escapes from the cylinder, from condensing and causingcarbon to be deposited on the valves, valve seats and other internal surfaces of the head over which the escaping air fiows. In a compressor equipped with a valve structure of the kind previously described it is practicable to cool that portion of thehead which is immediately adjacent the side wall of the cylinder, because the dis charge valves 2 are so arranged that the compressed air will escape through the discharge ports without liability of coming in contact with or flowing over the water-jacketed por tion of the head adjacent the side wall of the cylinder. Accordingly, in instances where it is necessary or desirable to cool the portion of the head immediately adjacent the upper end of the side wall of the cylinder, it is essential that the discharge valves and the ports or passageways which said valves control be so disposed or arranged that the compressed air escaping from the cylinder will not impinge upon and thus be cooled by the abovementioned jacketed part of the head. As

previously explained, the chamber 6 into which the compressed air is discharged from the. cylinder, and through which said air flows to the outlet, is provided with walls or surfaces which are so proportioned and arranged that they will not be scrubbed or contacted by the high velocity of air, and hence, the heat in said walls or surfaces will not be abstracted rapidly by the escaping high velocity air. In my improved compressor the valve seat member, the valve abutment members arranged above and below the same, and the major portion of the area or surface of the head remain in a highly heated condition when the compressor is in operation. Accordingly, carbon will not be formed in the head in such quantities or amounts as to require the compressor to be shut down and the valves of same cleaned at frequent intervals, as is necessary with practically all of the various makes of air compressors now in the market.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In an air compressor, the combination of a cylinder head having an internal space or chamber provided in its top wall with an opening, a valve structure adapted to be installed and removed through said opening and comprising a valve seat member whose diameter determines or controls the size of the hole in said top wall through which the valve structure is installed and removed, a seat on the head on which the peripheral portion of said valve seat member bears, a removable closure for said opening, and means carried by said closure for exerting a thrust on said valve seat member at a point far enough inwardly from the peripheral edge of same to insure said member bearing evenly on the seat provided for same on the head.

2. In an air compressor, the combination of a cylinder head provided with an internal space or chamber having an opening in the top Wall of same, a valve structure adapted to be installed and removed through said opening and comprising a valve seat member provided with a flat surface that is adapted to bear upon a seat on the head, the periphery of said valve seat member being separated by a space from a portion of the head that surrounds said valve seat member, a: removable closure for the opening in the top wall of said chamber, and means carried by said closure for exerting a downward thrust on said valve seat member at a point remote from the peripheral edge of the said member.

3. In an air compressor, the combination of a cylinder head, a removable valve structure in the head comprising a valve seat member that bears upon a seat on the head, a valve abutment member arranged below said valve seat member and supported by the head, means for clamping said valve seat member on its seat, and a cushioning device between the head and the bottom abutment member that is capable of yielding during the operation of clamping said valve seat member against its seat.

4. In an air compressor, the combination valve seat member contacts so as to produce a gasetight' joint, a valve abutment member supported by the head and arranged underneath said valve seat member, and means for securelyv supporting said valve abutment member and at'the same time permittinga gas-tight joint to be produced between said valve seat member and the head.

'5. In an air compressor, the combination ofa cylinder head, a removable valve struc ture in said head comprising a valve seat member, a seat on the head on which said valve seat member bears, a'valve abutment member supported by the head and arranged underneath the valve seat member, and a deformable device interposed between the valve abutment member and the surface'of the head which supports said member.

,6. In an air compressor, the combination of a cylinder head, a removable valve struc ture in said head comprising a valve seat member having air ports or passageways of relatively great cross-sectional area through which air enters and escapes fromthe cyl inder, a plurality of disk-shaped inlet valves that act on seats on the underside of said'memher, and a plurality of disk-shaped discharge valves that act on seats on thetop side of said valve seat member.

'Z. In an air compressor, the combination of a cylinder head, a removable valve structure in said head comprising a valve seat member having air ports or passageways of relatively great cross-sectional area through which air enters and escapes from the cylinder, a plurality of disk-shaped inlet valves that act on seats on the underside of said member, a plurality of disk-shaped discharge valves that act on seats on the top side of said valve seat chamber, valve abutment members arranged above and below said valve seats, and coiled springs seated in pockets in said valve abutment members.

8. In an air compressor, the combination of a cylinder head, a removable valve structure in said head comprising a valve seat member having air ports or passageways of relatively great cross-sectional area through which air enters and escapes from the cylinder, a plurality of disk-shaped inlet valves that act on seats on the underside of said member, a plurality of disk-shaped'discharge valves that act on seats on the top side of I of a cylinder head, a removable valve structure in said head comprising a valve seat member having air ports or passageways of relatively great cross-sectional area through which air enters and escapes from the cylinder, a plurality of disk-shaped inlet valves that act on seats on the underside of said member, a plurality of disk-shaped discharge valves that act on seats'on the top side of said valve seat member, a seat on the head on which the peripheral portion of said valve seat member bears, valve abutment members arranged above and below the valve seats on said valve seat member, and means for producing a gas-tight joint between said valve seat member and the head.

10. In an air compressor, the combination of a cylinder head, a removable valve structure in said head comprising a valve seat member having air ports or passageways of relatively great cross-sectional area through which air enters and escapes from the cylinder, a plurality of disk-shaped inlet valves that act on seats on the underside of said member, a plurality of disk-shaped discharge valves that act on seats on the top side of said valve seat member, valve abutment members arranged above and below said valve seats, springs carried by said abutment members for holding the valves sea-ted, means for clamping the bottom abutment member to the valve seat member, the chamber in the head in which the valve structure is positioned being provided in its top wall with an opening through which the valve structure can be inserted and removed, a closure for said opening, and means carried by said closure, for producing a tightjoint between the closure and top abutment member and for forcing the valve seat member tightly against the seat provided for same on the head.

FRANK AGKERMAN. 

